The present invention is directed to the tuning of a stringed musical instrument, such as a guitar. Further, it is directed to the use of free-to-vibrate parts in such an instrument for reinforcing and enhancing the vibrating characteristics of the instrument.
Basically, a stringed musical instrument is a hollow wooden box serving as a support for a number of strings secured in tension on an outside surface of the box. When the strings are plucked or bowed, they produce complex vibrations transmitted through the bridge or string supports to the wooden box causing its various surfaces to oscillate and setting in motion the air within, and surrounding the box, causing audible sound. obtaining the desired musical effect can be very difficult. In completely acoustic instruments, as compared to instruments using electronic means for amplification and modifying the tone of the instrument, such as those belonging to the violin family and the folk guitar, the wooden box is constructed to oscillate at a number of determined broad resonances for reinforcing the corresponding range of notes played on the instrument. When the tuning of the instrument is maintained, it will have an apparent increase in volume and sustain and generally will be more pleasing to the ear.
In a stringed musical instrument, such as a guitar, the strings extend unsupported between a first critical point on a neck of the guitar and a second critical point on the guitar body. The first critical point is usually formed by a nut supported in the neck. Generally, the second critical point is formed by a bridge element constituting part of a bridge or a combined bridge and tailpiece assembly. Traditionally, the size of the bridge elements is quite small and functions to clearly define the second critical point and can range from a narrow edge to a rounded surface with a diameter no larger than about 5/32". The strings are typically secured beyond the nut by tuning keys and beyond the bridge element by the tailpiece or tailpiece portion of a bridge and tailpiece assembly. Fine tuning the strings has long been a problem for guitars.
In fine tuning or changing the pitch of a string, two different operations are carried out. In one operation, the length of the string between the first and second critical points is adjusted, such as between the nut and the bridge element, and this is known as harmonic tuning. The second operation involves increasing or decreasing the tension on a given string for raising or lowering the string pitch. This second operation is generally characterized as pitch tuning. In practice, initially harmonic tuning is carried out and then pitch tuning.
A problem existing in tuning the strings is that the two different tuning operations tend to conflict. In harmonic tuning, the pitch is lowered when the distance between the critical points is increased and, conversely, when the distance is shortened, the pitch is raised. In pitch tuning, when the tension is increased, the pitch is raised and when the tension is decreased, the pitch is lowered. These different operations present difficulties in pitch tuning and maintaining the tuned condition of a stringed musical instrument.
When a fulcrum tremolo is used, there is the tendency when increasing string tension and raising of pitch, also to increase the length of the string, and, conversely, when decreasing string tension and lowering pitch, also to decrease the string length. Accordingly, when using a fulcrum tremolo, these counteracting features are not always balanced.
With the development of the fulcrum tremolo, that is, where the bridge plate is pivoted to provide a tremolo or vibrato effect, the problem of maintaining an effective pivoting action and assuring the return of the bridge plate to an initial position has presented problems. Often, the solution of one problem in pivoting the bridge plate has resulted in the introduction of another problem. As an example, when the bridge plate is pivoted, there is a tendency to upset the harmonic tuning of the strings. Further, the pivot support of the bridge plate, such as disclosed in the Rose U.S. Pat. No. 4,171,661, presented problems in maintaining the proper pivoting action, in returning to the original tuned position, in limiting the range of pivotal movement, and in maintaining the pivot means free from wear. If pivoting of the bridge plate results in wear of the surfaces at which the pivoting action takes place, friction is introduced into the movement of the bridge plate which interferes with its return to the initial position and original tuning.
Combination bridge and tailpiece assemblies have been known for some time. In the Kaufman U.S. Pat. Nos. 1,839,395 and 2,241,911 and in the Beauchamp U.S. Pat. No. 2,152,738, such assemblies were disclosed affording means for varying the tension on the strings and creating a tremolo effect.
In the Proelsdorfer U.S. Pat. No. 2,304,587, string tensioning devices placed on the tailpiece for fine tuning the pitch of the strings of violins, guitars and the like, were disclosed, however, such pitch adjustment is quite limited in range and designed to offer minor adjustment of pitch rather than raising and adjusting from an untensioned condition the strings by the tuners placed on the head of the instrument.
The first fulcrum tremolo combining the bridge and tailpiece was set forth in the Fender U.S. Pat. No. 2,741,146. In this patent, a bevelled ridge portion of the base plate was secured to the instrument body by six screws for permitting limited pivotal movement about the fulcrum and thereby varying the tension on the strings and producing the desired tremolo effect. The strings were supported in the traditional manner on top of the base plate by bridge elements adjustable in height and for string lengths, that is, harmonic tuning. As in known combination bridge and tailpiece assemblies, the strings extend vertically through openings behind the bridge elements and are secured in the tailpiece which in this case also functions to receive the string tensioning biasing springs.
In the Rose U.S. Pat. Nos. 4,171,661 and 4,497,236, two improvements were established. In one improvement, the bevelled ridge portion of the base plate was arranged so that it could be received and held in a tapered slot between the head of the screw and a flanged shoulder, thereby increasing the range of pitch change and improving the return to the initial tuned position and provided for lateral height adjustment of the tremolo. The other improvement involved functionally and physically integrating the bridge elements with the known art of combining fine tuners with anchoring means. In effecting the fine tuning, the bridge elements were provided with a constant radius, so that harmonic tuning would not be effected when establishing fine tuning, however, fine tuning is limited to a range of about two musical pitches and is inadequate for bringing the strings to proper pitch for compensating string stretch, or achieving common alternate tuning commonly requiring a larger range of pitch change.
In the Shiboya U.S. Pat. No. 4,383,466, a pin was located in a hinge pivot to improve the return to the initial tuned position. This arrangement did not offer lateral height adjustment of the base plate and the field of rotation was not as great as in the Rose improvement.
With these various improvements, a number of problems remained in the known fulcrum tremolo related to the bridge element and its movement when the tremolo is pivoted. Since the second critical point is offset from the pivot axis, initially there is a tendency for the string height at the bridge to decrease when the base plate is pivoted toward the body with the strings contacting the finger board and causing an undesirable buzzing noise and/or deadening the sound of the strings. This phenomenon limits upward pitch change. In addition, there is a tendency for string length to increase when the pitch is raised and for the string length to decrease with the pitch is lowered acting counter to the desired effect. Furthermore, the different diameters and constructi on of the strings on the instrument cause the strings to stretch at different rates and lose pitch relationship.
Concerning this last problem, several improvements have been proposed in the Steinberger U.S. Pat. No. 4,632,005, the Jones U.S. Pat. No. 3,411,394 and the Hussino U.S. Pat. No. 4,648,304, however, none of them are directed toward the fulcrum tremolo. In the installation of the fulcrum tremolo, there is a problem in routing the cavity to receive the tremolo. At least one routing has been required for the biasing springs. A further problem experienced in guitars and, particularly, in electric guitars is establishing a formant where the various resonances of the instrument co-act with the vibrations of the strings to enhance playing quality. Due to centuries of trial and error in the development of the violin body, a very sophisticated formant has been achieved. This has not been the case for the guitar. Particularly in electric guitars, the wooden box can cause unwanted feedback, so that volume of the cavity in the wooden box is often reduced or completely eliminated, as in the case where a solid body is used. As a result, electric guitars depend greatly on electrical amplification for both volume and tone. In the current design theory of electric guitars, the use of metal and especially of steel bridges contribute such mass that it prevents what little resonances the rest of the instrument possesses from having much effect. Accordingly, the tone of such instruments is limited for the most part by the vibrational characteristics of the strings. Another problem is that some players tend to rest their hand on the fulcrum tremolo while playing and inadvertently move the tremolo and detune the instrument.
In stringed musical instruments, the vibration of the strings in combination with the other parts of the instrument, combine to provide the desired tone or sound of the instrument. In the U.S. Pat. No. 3,353,433, to J. D. Webster, a tuning fork is incorporated with a floating bridge arrangement. The bridge arrangement depends from the tuning fork and is supported entirely by the strings of the instruments. Accordingly, when the strings are plucked and set into motion the tuning fork is activated and in turn feeds energy hack through the bridge arrangement to the strings, the purpose of which is to keep the strings vibrating as long as the tuning fork vibrates. However, the actual pitch and strength or the vibrating of the tuning fork were not adequately considered and the result was unbalanced at best.
In conventional stringed instruments tuning pegs secure the strings at the head of the instrument. The pegs have an opening through which the string is passed and then tied. Problems exist for conventional peg tuning, such as the amount of peg tightening required and the need for adjustment to compensate for on-going tuning and normal string stretch which takes place during use. As a result, fine tuners have been provided on the bridge or tailpiece. Further, often there is a relatively long distance between the nut and the tuning pegs where the string bends causing unequal tension on opposite sides of the nut and tuning problems. One proposed solution employs string clamps on the nut, however as often happens the string stretches beyond the adjustment range, of the fine tuners. Accordingly, the required correction, is tedious and time consuming involving unclamping, readjusting of the clamp, returning, reclamping and further readjustment.